1. Technical Field
The present invention relates to a method and apparatus for forming a three-dimensional object and in particular to a method and apparatus for forming a beam.
2. Description of the Background Art
Beams are increasingly used as support structures for the coachwork or body structure of automobiles and for use as support members for front and rear bumpers. The inventors of the present invention have disclosed a method and apparatus for curving three-dimensional closed profile beams in a plane parallel to the plane of movement of a forming tool in granted U.S. Pat. No. 6,185,978. As automobile design is continuously evolving, new shapes and forms are required for the beams which provide the support structure for the body of the automobile. Therefore, it is now desirable to form beams having a large variety of shapes and forms over and above beams curved in one plane as disclosed in the prior art. However, it is also desirable to retain the efficiency associated with manufacturing processes which may be incorporated into high volume production techniques.
It is an object of the present invention to provide an apparatus and method for the forming of three-dimensional objects and in particular beams which are required to have complex forms by using an efficient forming process for the beams which may be incorporated into existing high volume production techniques.
Accordingly, the present invention provides an apparatus for forming three-dimensional objects in particular three-dimensional beams comprising a support means and an actuation means characterized in that the support means has a number of support members spaced about the longitudinal axis of the support means where each individual support member locally defines an opening for supporting a section of the beam and the position of adjacent openings relative to one another defines the overall form of the beam wherein the actuation means defines the position of each opening.
Preferably, the openings define a position and a shape for a section of a beam within a plane substantially perpendicular to the longitudinal axis of the support means.
Ideally, the support members are also movable in a direction parallel to the longitudinal axis of the support means.
Preferably, the support members are independently operable.
Ideally, each support member is provided as a separable tool having two corresponding halves.
Preferably, each half of the tool is provided with its own actuation means.
Ideally, the actuation means includes physical ramps leading into the openings defined by the support members.
Ideally, the actuation means includes at least one axially adjustable shaft.
Preferably, the shaft is telescopic.
In one embodiment, the actuation means provides support frames for receiving the shafts.
Preferably, the support frames define channels which extend longitudinally on at least two opposite side members of each support frame.
Ideally, the shafts are movably mounted about the channels.
Preferably, the support frames are substantially rectangular.
Additionally, the actuation means provides housings for receiving the support frames.
Preferably, the housings are cylindrical.
Ideally, the support frames are rotatably mounted about the cylindrical housings.
Ideally, the actuation means is operated by mechanical, electrical, pneumatic or manual means.
Preferably, the actuation means is remotely operable.
Ideally, the support members are formed for receiving beams having a variety of cross-sectional shapes.
Preferably, the support members are formed for receiving cylindrical and non cylindrical beams.
Ideally, the apparatus includes a quenching means.
Preferably, the quenching means is provided by a water dispenser mounted on or about the apparatus.
Optionally, the entire apparatus may be enclosed in a chamber and gas is dispensed into the chamber to quench the newly formed beam.
Ideally, the apparatus comprises a mounting means for mounting the apparatus on a production facility.
Preferably, the actuation means is remotely operable in response to a control program running on a control unit.
Ideally, the control programme contains information regarding the relative location of a beam and each support member and the desired form of the beam at each point of contact with each support member.
The present invention also provides a method of forming three-dimensional beams characterised in that sections of the beam are formed locally by support members and adjacent support members are positioned relative to one another to define the overall form of the beam.
In one method, the beam is first engaged by the support members and then formed into a desired overall form by adjustment of the individual support members by the actuation means.
In another method, sections of the beam are first biased by ramps into openings located relative to one another and then formed locally by the openings in the support members.
Preferably, the corresponding halves of the tool on either side of the beam are moved towards one another by the actuation means and the beam is biased into the openings by the interaction of corresponding ramps as a result of the movement of the tool halves towards each other.
Preferably, the beam is preformed by any suitable manufacturing process and is preheated to a predetermined temperature for forming.
Ideally, suitable manufacturing processes include roll forming and blow moulding.
Preferably, the forming is carried out at one workstation.
Optionally, when the beam is non-cylindrical, the method of forming the beam includes twisting of the beam about its longitudinal axis.
Ideally, the method of forming the beam includes quenching of the beam after forming has taken place.